Operating mechanisms for casement windows or like swinging closures are known in the prior art in many forms, and these mechanisms vary in comparative simplicity and cost, strength and convenience of operation. Commonly, casement window operating mechanisms are not universal in the sense that right and left hand window sashes require the use of non-identical right and left hand operating mechanisms, which obviously increases the cost of window installation.
One of the objectives of this invention is, therefore, to provide practical, convenient, compact, sturdy and economical operating mechanism for casement windows which is universal or non-handed.
The prior art also teaches numerous locking arrangements for casement windows many of which are separate from the sash operating mechanism and therefore do not come into play automatically when the sash moves to a closed position. At least one prior United States patent, namely U.S. Pat. No. 3,438,151, issued to Evers, discloses a locking arrangement which includes a component carried by the sash and a coacting component carried by the sash operating linkage or mechanism which is not universal. This requires not only right and left hand sash operating mechanisms but right and left hand locking components on the sash and mechanism which engage automatically when the casement window is closed.
A further important object of this invention is to improve on the locking arrangement in the above-noted Evers et al. patent by providing directly in the universal or non-handed sash operating mechanism interengaging locking elements which come into play automatically to securely lock the sash regardless of whether a right or left hand installation is involved.
Additional features of the invention reside in the provision of a highly compact, smooth-acting and durable mechanism which is easy to operate and offers a high mechanical advantage during the final sash closing movement where resistance forces impeding closing are the greatest.
Other features and advantages of the invention will become apparent during the course of the following description.